TXT Input: Heuristic processing enables smarten punctuation.

src/calibre/ebooks/txt/input.py

@@ -14,7 +14,8 @@ from calibre.ebooks.chardet import detect
 from calibre.ebooks.txt.processor import convert_basic, convert_markdown, \
     separate_paragraphs_single_line, separate_paragraphs_print_formatted, \
     preserve_spaces, detect_paragraph_type, detect_formatting_type, \
-    normalize_line_endings, convert_textile, remove_indents, block_to_single_line
+    normalize_line_endings, convert_textile, remove_indents, block_to_single_line, \
+    separate_hard_scene_breaks
 from calibre.ptempfile import TemporaryDirectory
 from calibre.utils.zipfile import ZipFile
 
@@ -114,6 +115,7 @@ class TXTInput(InputFormatPlugin):
         if options.formatting_type == 'heuristic':
             setattr(options, 'enable_heuristics', True)
             setattr(options, 'unwrap_lines', False)
+            setattr(options, 'smarten_punctuation', True)
 
         # Reformat paragraphs to block formatting based on the detected type.
         # We don't check for block because the processor assumes block.
@@ -121,6 +123,7 @@ class TXTInput(InputFormatPlugin):
         if options.paragraph_type == 'single':
             txt = separate_paragraphs_single_line(txt)
         elif options.paragraph_type == 'print':
+            txt = separate_hard_scene_breaks(txt)
             txt = separate_paragraphs_print_formatted(txt)
             txt = block_to_single_line(txt)
         elif options.paragraph_type == 'unformatted':
@@ -132,6 +135,7 @@ class TXTInput(InputFormatPlugin):
             txt = preprocessor.punctuation_unwrap(length, txt, 'txt')
             txt = separate_paragraphs_single_line(txt)
         else:
+            txt = separate_hard_scene_breaks(txt)
             txt = block_to_single_line(txt)
 
         if getattr(options, 'enable_heuristics', False) and getattr(options, 'dehyphenate', False):

src/calibre/ebooks/txt/processor.py

@@ -120,6 +120,15 @@ def separate_paragraphs_print_formatted(txt):
     txt = re.sub(u'(?miu)^(?P<indent>\t+|[ ]{2,})(?=.)', lambda mo: '\n%s' % mo.group('indent'), txt)
     return txt
 
+def separate_hard_scene_breaks(txt):
+    def sep_break(line):
+        if len(line.strip()) > 0:
+            return '\n%s\n' % line
+        else:
+            return line
+    txt = re.sub(u'(?miu)^[ \t-=~\/]+$', lambda mo: sep_break(mo.group()), txt)
+    return txt
+
 def block_to_single_line(txt):
     txt = re.sub(r'(?<=.)\n(?=.)', ' ', txt)
     return txt